As shown, together with the equipment for G gravity ski enthusiasts from the ski ramp starting from rest along the ramp ABC downward slide, slide to the B point to increase the friction force by changing the skier ski way of size, make it in the end end point C at the right speed reduces to zero. The known AB>BC, two in the process of movement of the friction force are constant. The following are the image skier displacement velocity and acceleration, friction force changes with time, which is correct
Skiers from rest down, as long as the mgsin theta greater than the friction on the line, the friction is smaller than gravity G, slow decline period as long as the friction is greater than mgsin theta appropriate values on the line, does not necessarily require gravity friction is greater than G, more than G of course also, to see the problem is the radio or checkProblem is, RadioButtonList just choose B, is a multiple choice, D is optional, because the D option is a possibility, there is another possibility (two friction were less than the gravity G).
In the V-T image, the slope represents the acceleration, so the B pair; since it is uniformly accelerated, the acceleration value is constant, so C is wrong;
In the X-t image slope velocity, acceleration deceleration skiers first, the slope should be increased first and then decreased to A, the wrong; the problem set at both ends of the friction force are constant, so the skiers do uniform variable motion, and acceleration acceleration value is less than the deceleration acceleration
